Connect. Please help


I have tube pre amp with 2 pre out. I have 2 set speakers. I have 1 stereo amp and set of mono block amp. 
Can i connect pre out 1 to mono block amp and pre out 2 to stereo amp, if i listen stereo amp I will keep the mono block OFF or listen mono block I will keep the stereo amp OFF? Thank for help
Pre Amp Unison Research Mystery 2
Mono Block  Vincent SP998
Stereo amp Parasound Halo A21
nguyen828

Imhififan got you what you need to watch out for about the Vincent hybrids. Hopefully saves you some head scratching. I suspect your SP998 has the same design approach and may need to power it up.

Keep us posted.

Here my setup, 1 room 2 set speakers (depend what music i want to listen)
Auralic Altair RCA to in Mystery Pre and out to Mono to VR4Jr. Second pre out to B&W sub( I think this setup good)
I connected another XLR out put from Auralic direct to Halo A21 to Opera Seconda . I do not like the sound without pre amp. That why i am thinking to disconnect second pre out to sub and connect to Halo, use Halo loop to B&W sub. Because i don't  think VR4jr need sub. Please help! Thanks for all advice
Merry Christmas to everyone